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  Home > JCE Print > Journal of Chemical Education > Issues > 1999  > March  >
In the Laboratory
Variable Path-Length Cells for Discovery-Based Investigation of the Beer-Lambert Law
Sarah A. Stewart and André J. Sommer
Molecular Microspectroscopy Laboratory, Department of Chemistry and Biochemistry, Miami University, Oxford, OH 45056
Cover
March 1999
Vol. 76 No. 3
p. 399
Abstract
An economical approach to the variation of path length for visible absorption measurements is demonstrated. The method is particularly useful for discovery-based learning of the Beer-Lambert law. Polycarbonate inserts are employed with standard 1-cm plastic cuvettes to reduce path length. Inserts with nominal thickness of 0.063, 0.125 and 0.250 in. can be used singly or in combination to provide a wide variety of path lengths. The inserts are made of readily available materials and are economical and nearly indestructible. Their use requires no instrument modification. Experiments conducted to validate their applicability show R2 values of 0.998 over a path length range of 0.158 to 1.00 cm for standard solutions.

See Letter re: this article.
More Information
*  Citation
 Stewart, Sarah A.; Sommer, André J. J. Chem. Educ. 1999 76 399.
*  Keywords
 Instrumental Methods; Aqueous Solution Chemistry; Chemical Education Research; Laboratory Instruction; Teaching / Learning Aids; UV-Vis Spectroscopy
*  History
 Created:
Last Updated:		 June 15, 1999
June 22, 2005
Link to Letter added (April 2004).
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  Home > JCE Print > Journal of Chemical Education > Issues > 1999 > March > Page 399


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